A Sunken Lake
Did you know that there are underwater rivers? It sounds like something straight out of a science-fiction book, but it’s actually true. The picture below shows an incredible underwater river, which measures one kilometer in width, and its deepest point is slightly over 35 meters! If we were to lift this underwater river and place it above ground, it would be the 6th largest river in the entire world.
So, how did this underwater river come to be? Nobody knows for certain, but scientists speculate that this particular river was caused by salt water from the Marmara Sea entering the Black Sea several thousand years ago. Over time, the denser salt water eroded the rock formations at the bottom of the Black Sea, leaving this beautiful piece of natural art.